Anti-MAP2K3 (phospho S189) Antibody - Identical to Abcam (ab131283) and Novus (NB100-82048)

This rabbit polyclonal IgG from Antibodies.com is supplied at 50 µl as an unconjugated, affinity-purified reagent that specifically recognizes MAP2K3 (also known as MKK3 or MEK3) only when phosphorylated at serine 189. The immunogen is a synthetic phosphopeptide corresponding to residues surrounding Ser189 in human MAP2K3, and non-phospho-specific immunoglobulins are removed during purification by passage through a non-phosphopeptide column, leaving a reagent that reports on the catalytically engaged state of this dual-specificity kinase.

Validated for western blot, immunohistochemistry on paraffin sections, and immunocytochemistry/immunofluorescence, the antibody is recommended at 1:500–1:1000 for western blot, 1:50–1:100 for IHC-P, and 1:100–1:200 for ICC/IF. Predicted band sizes of 39 kDa, 53 kDa, and 81 kDa correspond to known MAP2K3 isoforms, and PMA-treated HeLa lysates have been used as a positive control in published western blot data. Reactivity is reported on human and rat samples, and the unconjugated format lets researchers pair the reagent with HRP, biotin, or fluorophore-conjugated secondary antibodies of their choice.

Because Ser189 lies within the activation loop of MAP2K3, this phospho-specific tool is commonly used to monitor stress-activated kinase signaling through the p38 MAPK cascade, including inflammatory and cytokine-driven responses. Applications include tracking induced versus basal MAP2K3 phosphorylation in cell lysates and in formalin-fixed paraffin-embedded tissue sections, supporting studies in signal transduction, cellular stress biology, and inflammation-related disease models.